The present invention relates to a plastic container, and more particularly to a vehicle oil tank which is made of plastic and provided with a filter.
In recent years, there is a demand for employing a plastic container as a vehicle oil tank in view of lightening a weight and decreasing a production cost. In order to satisfy this demand, various plastic containers have been developed.
Japanese Patent Provisional Publication No. (Heisei) 8-121138 discloses a plastic container employed as an oil strainer. This plastic container is produced by butting first and second container members and by executing injection welding onto an outer peripheral area of the butted surfaces so that a plastic belt is formed on and fixedly connected to the outer peripheral area by this injection welding.
However, such a conventional plastic container tends to generate strain during the welding since high-pressure melting plastic is injected on the outer periphery of the container.
It is an object of the present invention to provide a plastic container which has a structure that ensures a high-accuracy in dimension and prevents strain from being generated by injection welding, and to further provide a method of producing this improved plastic container.
A first aspect of the present invention resides in a plastic container which comprises a first container member comprising a first butt portion, a second container member comprising a second butt portion butted with the first butt portion, an inner member comprising a cylindrical portion and a band member formed on the first and second butt portions by injection welding, the inner member being disposed in a space defined by the first and second container members, the cylindrical portion of the inner member being engaged with the first and second butt portions, and the band member fixedly connecting the first and second butt portions.
Another aspect of the present invention resides in a method for producing a plastic container enclosing a filter. The method comprises a step of molding first and second tank members, respectively, a step of molding an inner member having a cylindrical flange portion and an annular clamped portion, a step of assembling the first and second tank members and the inner member so that the cylindrical flange portion of the inner member is engaged with the inner surfaces of the first and second tank members and that the annular clamped portion of the inner member is clamped by butt portions of the first and second tank members, and a step of welding an outer peripheral portion of the butt portions and the annular clamped portion to form a plastic annular band on the outer peripheral portion.